The present invention relates to fixing elements for reinforcement connection with a secondary action, especially for earthquake-resistant securement.
Reinforcement rods are frequently used to strengthen building structures using a hardenable composition in the drill hole. It has proved a disadvantage that, during the lifetime of the fixing, large cracks occur in the concrete, especially in the event of shock loading, such as during an earthquake, and the anchoring can fail.
Fixing elements are known which consist substantially of a threaded bolt, an expansible sleeve and an expander body with expander cone that can be drawn into the expansible sleeve. The expansible sleeve has longitudinal slots, which allow the expansible sleeve to expand as the expander body is drawn in. These fixing elements are generally set in an undercut drill hole with which the expanded sleeve forms an interlocking fit.
European patent document EP 0 455 952 Bi describes a fixing element for fixing in a substrate affected by momentary shock loading, such as that occurring during an earthquake. To avoid failure of a fixing in the event of shock loading, in this case a bolt and a complementary expansible sleeve are proposed. The expansible sleeve has two expanding portions, the first cylindrical portion having the smallest diameter of the expander cone and a second conically widening portion having the largest diameter, the continuation of which is cylindrical. It has proved to be a disadvantage of the known fixing element that in the event of shock loading considerable axial slippage occurs, and the component becomes loose, so that a new fixing element has be used following the overloading. Furthermore, mounting in an undercut is complicated, because the undercut has to be prepared, and for many applications is too expensive.
An anchor stud for a synthetic resin adhesive is known, having a shank that has several cones arranged in the axial direction european patent document (EP 0 356 425). This known anchor stud is set in the drill hole by means of a hardenable composition. This known anchor stud is not suitable as a replacement for a reinforcement rod, since only the proper standardized reinforcement rods permit a reinforcement connection.